1. Field of the Invention
The present invention relates to an electric toothbrush and a linear oscillator for the electric toothbrush.
2. Discussion of the Background
FIG. 3 shows an electric toothbrush of background art. Referring to FIG. 3, an electric toothbrush includes a linear oscillator 17. The linear oscillator 17 includes a shield case 16, a drive shaft 2 provided in the shield case 16 to be linearly movable. On the drive shaft 2, a vibration-absorber 12 is mounted in the axis direction with a distance from the plunger 3 so that the vibration-absorber 12 slides freely along the drive shaft 2. A brush part 1 is detachably attached to one shaft end (2a) of the drive shaft 2. A movable part 18 includes the drive shaft 2 and the plunger 3. A drive part includes the movable part 18 and the brush part 1.
In the electric toothbrush, in order to decrease the size of the linear oscillator 17, the space in which the vibration-absorber 12 vibrates is minimized. Thus, the weight of the vibration-absorber 12 is quite smaller compared to the weight of the drive part 19. In this linear oscillator, to give the specific oscillation or amplitude to the drive part 19, it has become necessary to make a larger magnetic circuit. As a result, the size of the linear oscillator 17 as a whole increases, and the number of parts also increases.